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6th Grade Science / Lesson 2 - Properties of Minerals
|Properties of Minerals
|What will we be learning today?
- In this lesson, we are going to learn about the properties of minerals.
- We will begin today's lesson, by listing the properties of minerals and explain each property.
|Properties of Minerals are:
- Luster is the way a mineral reflects light. There are two main classes: the metallic minerals and the nonmetallic minerals. A metallic mineral will have a shine to it when light strikes it. (metallic, pearly, glassy, silky and greasy) A nonmetallic luster, or dull appearance, will occur in nonmetallic minerals.
- Color is the general appearance of the mineral but is the least reliable property to help identify a mineral.
- Texture is the size of the grain or crystals in the rock. The grains may be coarse, fine, or nonexistent.
|Hardness is measured by seeing how easy it is to scratch a mineral. For example, talc, the softest mineral known, can be scratched with a fingernail. Diamond, the hardest mineral, can scratch all the other minerals but cannot be scratched by them.
In 1822, a German mineralogists, Friedrich Mohs, developed a ten-point scale of hardness. The same scale is used today.
Here is the Mohs hardness scale:
- Talc Least Hard
- Diamond Most Hard
- Streak is the color of the streak obtained by rubbing a mineral across a hard, rough surface. The color of the streak made by a mineral is often different from the color of the mineral itself because of contact with air and water.
- Cleavage is how a mineral breaks along flat surfaces in a very definite way.
- Fracture is how a mineral looks when it breaks apart in an unevenly or irregular way.
- Density is the measure of how much matter there is in a given amount of space.
- Density is a ratio of an object's mass to its volume.
- Pick up a golf ball and ping pong ball, which will feel heavier ?
- The balls are the same size, the golf ball feels heavier because it's denser.